Ink-jet printing involves the placement of small drops of a fluid ink onto a media surface in response to a digital signal. Most ink-jet printers create printed images using print architecture, also commonly referred to as pens, which eject or jet small ink droplets through a printhead orifice onto a print media surface without physical contact between the printhead and print media surface. Some ink-jet printers contain a plurality of pens, each of which are dedicated to jetting a specific color of ink, and thus, in combination can provide a full color image. Generally, with one type of ink-jet printer, there is provided a pen having an ink reservoir which travels along a printing path with the pen in order to supply the pen with appropriate ink at appropriate times. Alternatively the ink reservoir is stationary the ink is fluidly coupled to moving printheads via delivery tubes. In either case, usually, a printer includes a single pen which is typically dedicated for jetting a black ink colorant, while a separate pen(s) is utilized for jetting cyan, magenta, yellow, and/or combinations or variations thereof.
As noted above, ink-jet pens typically include a printhead which has a plurality of tiny nozzles which displace or jet the ink onto the media surface. The nozzles are typically arranged in one or more linear or patterned arrays. For example, the nozzles (or orifices) can be a multi-linear array located side-by-side, parallel to one another, and substantially perpendicular to the printing direction. The printhead of a pen will also include an orifice plate which helps provide a smooth surface to aid in the printing performance. However, as the printhead passes over a print zone, the orifice plate tends to attract and pick-up contaminants, such as dust, paper fibers, paper debris, etc. The ejection of the ink through the orifice plate often causes ink accumulation which results in uncontrolled ink puddling. Ink puddling can result from misdirected drops, significant ink accumulation on the orifice plate, and pen servicing difficulties. As ink accumulation on the orifice plate can lead to print quality degradation, many methods have been developed to resolve these disadvantages and to improve print quality.
Of these methods, servicing print stations have been placed near the general printing mechanisms to aid in the ink and debris accumulation removal. However, servicing stations generally include cleaning the printhead with a wet and dry apparatus which in turn wears and/or damages protective layers that are sometimes applied to the printhead, thus diminishing the longevity and print quality exhibited by the printhead.
Another more complex approach to remedy the issue of ink accumulation is to apply a self-assembled monolayer onto the orifice plate surface. However, this approach provides only a temporary solution, as these materials are often easily damaged and are difficult to repair. For example, a single application of the self-assembled monolayer can be worn away or damaged after several cleaning installments, thus degrading the print quality once again. Part of the difficulty of repair comes from the fact that these materials are usually applied by dipping the orifice into an anti-wetting solution or spraying the anti-wetting solution onto the orifice. These approaches are difficult when an ink-jet pen is installed within a printer.